gammainc.cc File Reference

#include "lo-specfun.h"
#include "defun-dld.h"
#include "error.h"
#include "gripes.h"
#include "oct-obj.h"
#include "utils.h"

Include dependency graph for gammainc.cc:

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Functions

DEFUN_DLD (gammainc, args,,"-*- texinfo -*-\n\ @deftypefn {Mapping Function} {} gammainc (@var{x}, @var{a})\n\ @deftypefnx {Mapping Function} {} gammainc (@var{x}, @var{a}, \"lower\")\n\ @deftypefnx {Mapping Function} {} gammainc (@var{x}, @var{a}, \"upper\")\n\ Compute the normalized incomplete gamma function,\n\ @tex\n\ $$\n\ \\gamma (x, a) = {1 \\over {\\Gamma (a)}}\\displaystyle{\\int_0^x t^{a-1} e^{-t} dt}\n\ $$\n\ @end tex\n\ @ifnottex\n\ \n\ @example\n\ @group\n\ x\n\ 1 /\n\ gammainc (x, a) = --------- | exp (-t) t^(a-1) dt\n\ gamma (a) /\n\ t=0\n\ @end group\n\ @end example\n\ \n\ @end ifnottex\n\ with the limiting value of 1 as @var{x} approaches infinity.\n\ The standard notation is @math{P(a,x)}, e.g., Abramowitz and Stegun (6.5.1).\n\ \n\ If @var{a} is scalar, then @code{gammainc (@var{x}, @var{a})} is returned\n\ for each element of @var{x} and vice versa.\n\ \n\ If neither @var{x} nor @var{a} is scalar, the sizes of @var{x} and\n\ @var{a} must agree, and @code{gammainc} is applied element-by-element.\n\ \n\ By default the incomplete gamma function integrated from 0 to @var{x} is\n\ computed. If \"upper\" is given then the complementary function integrated\n\ from @var{x} to infinity is calculated. It should be noted that\n\ \n\ @example\n\ gammainc (@var{x}, @var{a}) @equiv{} 1 - gammainc (@var{x}, @var{a}, \"upper\")\n\ @end example\n\ @seealso{gamma, lgamma}\n\ @end deftypefn")

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Function Documentation

DEFUN_DLD	(	gammainc	,
		args
	)

Definition at line 35 of file gammainc.cc.

References octave_value::array_value(), octave_value::double_value(), error(), error_state, octave_value::float_array_value(), octave_value::float_value(), gammainc(), octave_value::is_scalar_type(), octave_value::is_single_type(), print_usage(), transform(), and x.